The present invention relates to an apparatus for forming holes in bone, especially in hip bone suitable for the insertion of an artificial socket for production of an artificial joint to the femur.
It is necessary that the tool used for this drilling be held carefully in a very precise position since the position of the aperture in the bone is critical for production of a proper artificial joint. Several types of apparatus are already known for maintaining a milling cutter or other drill in the desired working position. For example, optical aids have been used to permit adjustment of the drill. Another possibility is a total endoprosthesis (Judet system) which, similarly to the system described herein, incorporates an elongated tool carrier. This is constructed as a manually retained holding stem by one of whose ends the milling cutter is rotatably retained and can be manually intermittently rotated by means of a tool attached to it.
In several aspects, operation of this type of apparatus calls for technical skill on the part of the surgeon. On the one hand, it is essential that, from the beginning, the milling cutter or other drill is brought into engagement with the femur or other bone in a precise position, and this is a difficult operation since the apparatus must be held with one hand while the milling cutter is rotated with the other hand. Also, unsteadiness of hand resulting from intermittent rotation of the cutter causes canting of the cutter through a relatively small angle which, in turn, can result in bone particles being torn from the femur.